Dinosaur Extinction
Theories

Volcanism Theory - Dinosaur Extinction

Many
researchers believe that a number of the same physical events would have
occurred at the K-T boundary if either extensive volcanism or an asteroid
impact took place. It is also believed that some biological results would
be similar.

The volcanism and asteroid impact theories are equally weak in their
biological prediction. The major difference with these two theories is
in their timing.

The asteroid impact theory measures most of the cataclysmic effects in
months or years, with residual physical effects lasting possibly hundreds
or a few thousand years, the volcanism theory measures effects into the
millions of years.

Deccan
Traps
500 000 years before the K-T boundary and 200 000 years before the asteroid
impact massive volcanic activity began in India. A flood basalt eruptions
produced millions of cubic miles of new rock over hundreds or thousands
of years resulting in what is now know as the "Deccan Traps".

The Deccan Traps could have caused extinction by the release of dust
and volcanic material into the atmosphere blocking sunlight and thereby
reducing photosynthesis.

This massive volcanic activity exerted pressure in the biosphere causing
the gradual downfall of the dinosaurs and other cretaceous creatures.
It is argued that the Chicxulub impact was one of the many impact hits
the earth took during this time period.

It is believed that a second impact or possibly more which is often refereed
as the KT impact, was larger than the Chicxulub impact, was the final
event that pushed the dinosaurs into extinction and produced the iridium
layer.

The second impact's location has yet to be discovered, but tentative
evidence points to somewhere in the Indian Ocean. This second asteroid
impact also contributed to the extinction of the Cretaceous Period.